\xiti
\begin{xiaotis}

\xiaoti{已知角 $\alpha$ 的终边分别经过下列各点，求角 $\alpha$ 的四个三角函数值：}
\begin{xiaoxiaotis}

    \begin{tblr}{columns={9em, colsep=0pt}}
        \xxt{$(1,\; 2)$；} & \xxt{$(1,\; \sqrt{2})$；} & \xxt{$(2,\; 5)$；} & \xxt{$(\sqrt{2},\; \sqrt{3})$。}
    \end{tblr}
\end{xiaoxiaotis}

\xiaoti{求下列各式的值：}
\begin{xiaoxiaotis}

    \xxt{$3\tan{30^\circ} + \cot{45^\circ} - 2\tan{45^\circ} + 2\sin{60^\circ}$；}

    \xxt{$2\cos{30^\circ} - 4\cot{30^\circ} + 3\tan{60^\circ}$；}

    \begin{tblr}{columns={18em, colsep=0pt}, rows={rowsep=0.5em}}
        \xxt{$\dfrac{\cos{45^\circ} - \sin{30^\circ}}{\cos{45^\circ} + \sin{30^\circ}}$；}
            & \xxt{$\sin^2{45^\circ} + \cos^2{60^\circ}$；} \\
        \xxt{$\dfrac{3\cot{60^\circ}}{2\cos^2{30^\circ} - 1}$；}
            & \xxt{$\dfrac{\cos{60^\circ}}{1 + \sin{60^\circ}} + \dfrac{1}{\tan{30^\circ}}$。}
    \end{tblr}

\end{xiaoxiaotis}


\xiaoti{查表求下列三角函数值：}
\begin{xiaoxiaotis}

    \xxt{$\sin{28^\circ18'} \nsep \sin{57^\circ43'} \nsep \sin{68^\circ33'} \nsep \sin{72^\circ58'}$；}

    \xxt{$\cos{65^\circ2'} \nsep \cos{10^\circ36'} \nsep \cos{44^\circ15'} \nsep \cos{32^\circ4'}$。}

\end{xiaoxiaotis}


\xiaoti{查表回答下列问题：}
\begin{xiaoxiaotis}

    \xxt{$\sin{20^\circ} + \sin{40^\circ}$ 是不是等于 $\sin{60^\circ}$？}

    \xxt{$\cos{10^\circ} + \cos{20^\circ}$ 是不是等于 $\cos{30^\circ}$？}

\end{xiaoxiaotis}


\xiaoti{已知下列三角函数值，求锐角。}
\begin{xiaoxiaotis}

    \xxt{$\sin\alpha = 0.6841 \nsep \cos\alpha = 0.3241 \nsep \sin{A} = 0.5136$；}

    \xxt{$\cos{B} = 0.2839 \nsep \sin\beta = 0.0526 \nsep \cos\beta = 0.5412$。}

\end{xiaoxiaotis}


\xiaoti{查表求下列三角函数值：}
\begin{xiaoxiaotis}

    \xxt{$\tan{9^\circ19'} \nsep \tan{64^\circ10'} \nsep \tan{75^\circ39'} \nsep \tan{79^\circ51'}$；}

    \xxt{$\cot{8^\circ28'} \nsep \cot{16^\circ25'} \nsep \cot{48^\circ27'} \nsep \cot{88^\circ44'}$；}

    \xxt{$\sin{89^\circ32'} \nsep \cos{38^\circ43'} \nsep \tan{5'} \nsep \cot{14^\circ27'}$。}

\end{xiaoxiaotis}


\begin{enhancedline}
\xiaoti{已知下列三角函数值，求锐角。}
\begin{xiaoxiaotis}

    \xxt{$\tan\alpha = 0.7817 \nsep \cot\beta = 1.1106 \nsep \tan{A} = 1.0736$；}

    \xxt{$\cot{A} = 3.267 \nsep \tan{B} = 2.378 \nsep \cot{B} = 57.82$；}

    \xxt{$\sin{x} = 0.86276 \nsep \cos{x} = \dfrac{2}{3} \nsep \tan{x} = 53.10$。}

\end{xiaoxiaotis}
\end{enhancedline}

\end{xiaotis}

